Past distributed database technology involved a trade-off between processing throughput, and securing of consistency related to distributed transaction processing and exclusive control and of correspondence related to referential integrity. Two-phase commit technology and replication technology have been applied to secure the said consistency and said referential integrity so far, however practicable throughput was not able to be obtained, moreover it is applied to practical use and little has been heard of anyone obtaining sufficient results. On the other hand, when two-phase commit technology or replication technology is not used, possible distributed database of a real-time update has not been put to practical use in the former technology. What is called a distributed database allowing real-time update is actually just a virtual single database system applied to the secondary distributed storage medium. Moreover, on search sites or virtual store sites on the Internet, it is assumed the update system uses batches and the search system uses a distributed reading specialized type distributed database system.
Recently known is the system described in Patent Reference Document 1 shown in FIG. 1 where the distributed database system connects two or more said database domains including a database management system by peer to peer, manages information on status such as structure, exclusive controls of the database arranged and referential integrity during database domains as a meta data besides the main body data, has excellent scalability by mutually exchanging and synchronizing meta information on each same kind of meta information between each of the database domains and makes the database object minimize by a granularity arbitrary, and contributes to the localization of the trouble part and to minimize shortening of the restoration time. A concrete method to exchange said meta information was not referred to in Patent Reference Document 1, but at the time that the technology was developed that was described in Patent Reference Document 1 (the inventor of this invention conceived the idea of this invention around December 2001), the structure of software was becoming complex and installing and maintenance involved difficulty in synchronization by an individual exchange at each said meta information. Therefore, the simplification of the structure is hoped for. Moreover, further speed-up is demanded in recent years when expanding data is assumed to be a problem. The problem was solved this time by the method of the exchange of each small masses of memory equipped with meta information and not by individual exchange of the synchronization of said meta information but the use of partition topology technology and replication technology system, described in Non-Patent Reference Document 1.
Moreover, partition topology technology described in Non-Patent Reference Document 1, constructs ‘Cache technology system’ on the main memory of two or more computers including the virtual machine as shown in FIG. 2. And each memory cache is shared from two or more computers by the unit of memory cache on the main memory on each computer, and in the system that connects two or more computers not large comparatively and composes a huge-scale virtual machine comparatively, it is known as a technology that constructs a comparatively huge-scale virtual In-memory database system. However, it cannot be said that this is a method of achieving distributed database, and it is a method of achieving a comparatively huge-scale mere virtual single database system. As a result, the localization of the trouble part as storage is possible at the trouble. However, it doesn't become localization of the trouble part as database system. Therefore, the collection of the update journals for making and the roll forward of the snap shot for said consistency and backing up with said the referential integrity kept reaches the whole area of the database, then restoration in a short time is not easy because recovery reaches the entire database system.
Moreover, the technology which only has to access data on the main memory on own computer in the case of accessing data on the main memory on other computers, constructing ‘Cache technology system’ on the main memory of two or more computers including the virtual machine, making replication of the memory cache on the main memory on each computer, and synchronizing them mutually is described in a page of Non-Patent Reference Document 1 concerned. This is known as ‘Replication. However, it doesn't contribute to Scale Out because the shared amount of the memory cache does not increase even if the number of computers increases in this case.
In addition, the composition of general transaction system in which COMMIT is executed if all updates succeed, and in which ROLLBACK is done if as much as one update fails, is indicated in paragraph 0002 of patent document 4. In addition, it is indicated that there are “Nest transaction” and “Chain transaction” in paragraph 0013 as a technique for relating two or more transactions. A detailed explanation concerning “Nest transaction” is indicated in paragraph 0014 and paragraph 0015. Moreover, a detailed explanation concerning “Chain transaction” is indicated in paragraph 0016 and paragraph 0017.